"Unmountable: Unsupported partition layout" after power cut

[AlphaXL]

I just had a power cut and after I booted the server back up, I have one disk with: "Unmountable: Unsupported partition layout"

 

What is the best way to solve this so I wouldn't lose any data?

 

PS: I'm new to Unraid, just got my server up 2 weeks ago.

 

[JorgeB]

Please post output of:

 

fdisk -l /dev/sdh

 

[AlphaXL]

Disk /dev/sdh: 12.73 TiB, 14000519643136 bytes, 27344764928 sectors
Disk model: ST14000NM001G-2K
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 0D5DAF02-CD7C-4F29-9321-2594F511604D

Device     Start         End     Sectors  Size Type
/dev/sdh1     64 27344764894 27344764831 12.7T Linux filesystem

[JorgeB]

Partition isn't corrupt, so something changed the disk MBR, usually the easiest way to recover is rebuild that disk on top, Unraid will recreate the partition with the correct MBR, you can test by unassigning the disk and starting the array, Unraid will emulate the missing disk and it should mount immediately, assuming parity is in sync, if it mounts and contents look correct just rebuild on top.

[AlphaXL]

I unassigned the drive, started the array and looks like this now:

 

 

Is this how it should look and what would be the next step?

Thank you for helping out.

Edited February 18, 2022 by AlphaXL

[JorgeB]

Emulated disk is mounting, now just re-assign the disk to rebuild on top (or use a spare one if you want to play it safer).

[AlphaXL]

I re-assigned the drive and looks like it's rebuilding now. Is that correct?

 

 

Edited February 18, 2022 by AlphaXL

[JorgeB]

22 minutes ago, AlphaXL said:

Is that correct?

Yep.

[AlphaXL]

I had another power cut again now, during the rebuild 🤬 Unbelievable!

I will keep the server powered off until the electricity supply issues have been sorted out in my area.

I will update this topic here later.

[JonathanM]

34 minutes ago, AlphaXL said:

I had another power cut again now, during the rebuild 🤬 Unbelievable!

I will keep the server powered off until the electricity supply issues have been sorted out in my area.

I will update this topic here later.

Is your battery backup malfunctioning?

[AlphaXL]

7 hours ago, JonathanM said:

Is your battery backup malfunctioning?

I had just bought a new 1000VA UPS and it was not connected yet. 😔

 

 

It's not gonna happen again. Got my new UPS connected now.

Edited February 18, 2022 by AlphaXL

[AlphaXL]

Thank you for the help. All seems good:

 

[JorgeB]

Just out of curiosity what controller is that disk connected to? You can also post the diagnostics if you don't know, because what happened should never happen with just a power loss.

[AlphaXL]

That drive is connected to: LSI/Avago/Broadcom SAS 9300-8i HBA PCIe 3.0

 

Just to add... Power cut happened while I was copying files from unassigned disk into the array. Maybe that's why it wasn't mountable after powering back up?

 

That's my server:

 

- Intel Core i5-9600K 9th Gen Coffee Lake
- Cooler Master Hyper H412R
- ASRock B365M Phantom Gaming 4
- Crucial 32GB DDR4 RAM 2666MHz PC4-21300 CL19
- LSI/Avago/Broadcom SAS 9300-8i HBA PCIe 3.0
- Kingston DataTraveler Kyson 32GB USB 3.2 Flash Drive (Unraid)
- 112TB HDD storage (data array)
- 2×18TB HDD (parity array)
- 2×Samsung 970 EVO Plus NVMe M.2 SSD 1TB (cache pool)
- Seasonic CORE GC 650W 80 PLUS Gold
- 3×120mm BeQuiet! Pure Wings 2 PWM [intake]
- 2×80mm BeQuiet! Pure Wings 2 PWM [exhaust]
- Logic Case SC-415A 4U rackmount

- CyberPower BRICs LCD Series UPS 1000VA 600W

svalbard-diagnostics-20220219-1137.zip

Edited February 19, 2022 by AlphaXL

[JorgeB]

OK, that controller is usually fine, firmware is also latest, for there to be an invalid partition layout error it means the MBR was changed, that's the very beginning of the disk, outside the partition to where data gets written to, so that should never happen just because of a power cut, but you're not the first, not sure what the problem is, disk or controller would be the main suspects.

[AlphaXL]

I was running the same server/hardware on the latest Ubuntu Server the last 2 years (before switching over to Unraid) and had a few power cuts also during that time period and no issues with disks mounting after or anything like that. Of course I had no array or parity etc. Just separate disks and formatted in ext4 and full of data files.

 

I suspect that could it have been because I was copying files (writing into the array) when the power cut happened?

 

I will keep an eye on that disk and I will be swapping out smaller disks for bigger ones in the future anyway... So I might swap that one soon just to be on the safe side.

[JorgeB]

27 minutes ago, AlphaXL said:

I suspect that could it have been because I was copying files (writing into the array) when the power cut happened?

That shouldn't be a problem, since nothing should be written to or update the MBR area.

[AlphaXL]

10 minutes ago, JorgeB said:

That shouldn't be a problem, since nothing should be written to or update the MBR area.

Yes, makes sense.

 

Anyway.. thank you for helping out. Seems to be sorted for now at least.